The end all be all word used by teenage males when speaking to their parents. Used as a response to questions which they do not wish to answer.

Parent: how was school?
Son: ehh
Parent: did you have fun eating with your girlfriend after school?
Son: ehh
Parent: we cleaned your room
Son: ehh?
Parent: we need to have a talk about the condom wrappers we found
Son: uhhhhh

a word or expression used to show many emotions- embarrassment, shock, disgust, or just used in any point in a conversation. It has many, many variations and the simplest 'ehh' base serves as a model for other variations. As long as it has the distinct 'ehh' sound, one can improvise. Use with intonation.